• By Dartington SRU
  • Posted on Thursday 07th May, 2009

Stress study is given US press test

There's no shortage of evidence to suggest there is a causal link between poverty and chronic stress and between chronic stress and all manner of intergenerational setbacks.During the last decade or so, the research has been sharpened by improving understanding of brain chemistry and the physiological indicators of cognitive processes.One spin-off has been a new variety of political debate which makes surprisingly frequent allusions to neuroscience in the context of arguments about social justice. Advances in neuroendocrinology once considered obscure have become, just as surprisingly, newsworthy.The Washington Post, for example, lately covered work by Gary Evans, Professor of Human Ecology at Cornell, which is beginning to fine down insight into the impact of environmental disadvantage on cognition."Chronic stress from growing up poor appears to have a direct impact on the brain, leaving children with impairment in at least one key area – working memory," the Post reported.In a comparative longitudinal study of 195 children from households living above and below the poverty line, Evans and colleagues scored stress levels using a scale indicating “allostatic load” – a combination of measures of the stress hormones cortisol, epinephrine and norepinephrine with blood pressure and body-mass index data.The tests were run when the children were nine and 13, and at 17 working memory was assessed. "The longer they lived in poverty, the higher the allostatic load and the lower the working memory score," Evans found.In summarizing the value of the work, Avshalom Caspi, Professor of Psychology and Neuroscience at Duke University, told the Post that it showed how something outside the body could get under the skin and into the brain."What this article says is that one reason that poverty makes such an important difference is that it affects many physiological systems, and those systems, once stressed, may compromise brain development."Evans himself put the argument in simpler, more politicized terms. "It's not just 'Read to our kids and take them to the library,'" he said, presumably referring to Bush administration schemes like the 2004 No Child Left Behind Summer Reading Achievers Program. The top half of the story archived by The Washington Post and reprinted towards the end of April in the UK Guardian Weekly is straightforward enough, accounting for the journey made by a hypothesis from deep science to global circulation newspaper.But it's in the bottom half of the record, among the now de rigueur comments from readers, where a brighter light is is shed on the curious, evolving relationship between the understanding of neurocognitive or biological mechanisms and the cognition of Western society at large.Earlier this year Gary Evans was appointed to the Children, Youth and Families Board of the US National Academy of Sciences. That National Academy carries policy-recommending clout, and segments of The Washington Post readership seemed alive to the significance of his new association. So among the 170 or so comments on the Post’s dry reporting, there is an upswelling of feeling about stress and the “Liberal Agenda”.“So what about in adulthood?” wrote one. “What is the effect of the allostatic load in women from the chronic dangers and stresses of being treated as second-class citizens all their lives? What does the allostatic load do to the working memory of males who are shorter and more slenderly built than the bullies at school? And what does it do to members of any devalued racial or ethnic group in society?” And similarly, “But aren't there OTHER sources of stress besides income?!? aka 'poverty'. For example: What if the kid was really ugly. What if the kid was really fat. What if the kid had a speech impediment. What if the kid was gay in a redneck environment. What if the kid's dad got killed in Iraq because Bush lied. What if the kid had a fat ugly nose.etc, etc, etc. I could sit here all day and list conditions that put kids under a lot of stress.” And alternatively: “There is a pathologist in Alaska who has examined children through MRI brain scans comparing children with a zero Adverse Childhood Experiences (ACE) score (no adverse events like sexual abuse, physical abuse, alcoholism of a parent etc.) and the brain of a child with a very high ACE score. “The high ACE score child had very little happening in the frontal lobe, all the activity was in the base of the brain. This pathologist said our brains build the connects they need depending on their environment. A child in a dangerous environment needs to be hyper-alert, scanning constantly for danger. Cognitive focus is a luxury.”To read the source material, see: Childhood poverty, chronic stress, and adult working memory by Gary W. Evans and Michelle A. Schamberg on the National Academy of Sciences website.

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